1. Field of the Invention
The present invention relates to a filter contact comprising an electric contact in the form of a metal rod surrounded by a filter element of tubular shape which is fitted with a first electrode on its external face and with a second electrode on its internal face, said second electrode being electrically connected to the electric contact, the two electrodes being insulated from each other.
2. Description of the Prior Art
Filter contacts are particularly useful in electric connectors. A filter contact of this type is described in French Pat. No 2,185,879. The filter contacts described in this patent application are particularly intended for attenuation of high-frequency waves. The filter employed in this application consists of a tubular element of ceramic material in which is housed a tubular element of ferrite. There is thus obtained an LC filter having a cutoff frequency which depends on the value of these elements.
Although filter elements of this type permit suppression of HF waves which are liable to modulate an analog signal transmitted by the electric contact, they are usually ill-suited to protection of digital signals against spurious pulses which originate from various sources and exhibit high overvoltage in a random manner. Spurious pulses of this type are liable to modify the contents of the message transmitted in digital form, which is in turn liable to produce errors in the received signal.